New London Architecture

1 Undershaft

Planning Granted

1 Undershaft is located at the heart of the 'Eastern Cluster' of the City of London at the junction of St Mary Axe and Leadenhall Street. When constructed it will be the tallest building in the City.
Londons Tall Buildings Survey 2020

Londons Tall Buildings Survey 2020

1 Undershaft is located at the heart of the ‘Eastern Cluster’. When constructed it will be the tallest building in the City. The top of the 73-storey tower will be 289.94 m tall at a height of 304.94m AOD. The proposed building recognises the continued growth of the City of London with 1 Undershaft leading the next generation of buildings. It acknowledges the importance of culture and public realm for the people who live, visit or work in the City. As well as providing a new public space at street level, it will offer a generous space at the top of the building for a free public viewing gallery, education centre, exhibition space and London’s highest public restaurant.

 At 281.5m above ground, the public viewing gallery will be the highest in the City and the only one to offer an unobstructed 360 degree view of the capital. Alongside the public viewing gallery will be an education centre designed to help schools learn about the history of London. The public gallery and education centre with be occupied by Museum of London, with access to the public spaces will be free and available to all visitors.

New public space has been created to accommodate an increased number of pedestrians and cyclists, with the proposed public square extending beneath the building, opening up new public walkways. A large open landscape will lead down to an open court retail gallery of restaurants, cafes, amenities and shops

. The distinctive exterior gives the tower its rigidity. The external bracing made of weathering steel provides additional strength and draws its inspiration from the pragmatic beauty of our industrial heritage where economy of structure is coupled with bold form. Horizontal shades made of highly durable white vitreous enamel metal protect the glazed facades and give the tower a distinct white tone contrasting the green glazing of adjacent buildings. The tower is uni-directional, adding to the simplicity of the design its prominence in the central location in the City of London. The sides of the tower taper in slightly over the height of the building, designed to mirror the reduction of structural requirements as the building rises. If the lines were to be extended beyond the height of the tower they would eventually converge at a point ten times the height of the building.

 1 Undershaft provides a variety of uses: offices, a public viewing gallery, education centre, restaurant, extensive public realm and retail spaces. The offset core enables uninterrupted office space whilst the sky lobbies and the high-quality internal environment support the health and wellbeing of its occupants. Raised planters and seating areas are incorporated within the edge of the elliptical opening leading down to the retail gallery at lower ground. The lower court provides the opportunity for events and seasonal activity and also contains the entry to the viewing gallery, education space and restaurant. By shifting the core to the side and elevating the office reception off the ground a new space beneath the building will allow pedestrians to walk directly from Bishopsgate to Leadenhall Street. The new south facing public square and lower retail court will offer a new destination for people to meet and relax.

 ‘A building’s skin is incredibly important in terms of engagement with the external public realm. In our work, this realm extends well beyond the public square, incorporating the wider horizon of the City. The possibility that change brings to improve the public realm set against a balance of the appropriate massing and building scale is key to this future process. While the quality of building will continue improving, new voices can join the dialogue and offer a direction to its actual development’ Eric Parry, Director, Eric Parry Architects

Project information


Planning Granted


City of London


92000 sq m




122 Leadenhall St, Lime Street, London EC3V 4AB, UK

Team Credits


Eric Parry Architects


Aroland Holdings

Planning Consultant

DP9 Planning consultant

Structural Engineer


Cost Consultant


Pedestrian Wind & Tunnel Study x 2 plus Cladding 


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